1. Field of the Invention
This invention relates to an improvement of a film retriever in which a free end of the film which has already been rewound in the cartridge upon completion of photographing, and more particulary an automatic film retriever having a feature in which a free end of a standard 35 millimeter film which has already been rewound in the cartridge may be pulled out of it automatically and efficiently without damaging it or film.
2. Description of the Prior Art
Among amateur and professional photographers nowadays, one of the most popular and highly consumed film formats is the 35 millimeter size film having no light shielding sheet in it (hereinafter called as merely a film). The film is kept wound on a spool in a cylindrical light shielding case called a patrone or a cartridge (called a cartridge hereinafter), only a free end of the film is placed outside the film retrieving opening applied with a balck plush in order to increase the light shielding characteristic.
In this type of cartridge the film should be rewound into the cartridge so as to eliminate the exposure when the cartridge is to be loaded in a camera and removed from it upon completion of the photographing. Almost all of the cameras having the 35 millimeter film therein have no provision for enabling the rewinding of the film into the cartridge with only a free end of the film being remained outside the cartridge, so that the film is to be rewound upon photographing of all the film frames, it is quite natural to say that even the free end of the film might be wound into the cartridge. Therefore, as described above, in a processing laboratory complying with a request for developing and printing the film of which even the free end has already been rewound into the cartridge, one of the side caps of the cartridge is normally removed from a cylindrical main body of the cartridge by utilizing a mechanical force and the spool on which the film is wound is removed from the main body of the cartridge, so that it is often recognized that the cartridge may not be used again. Further, as described above, since removing one of the side caps from the main body of the cartridge means that each of the main body of the cartridge, one of the side caps and the spool is separated from one another, this operation will require not only a management over these operations but also, as described above, causes some troubles in which one of the side caps is scattered away when one of the side caps is removed from the main body of the cartridge and in which surplus burden is applied to the operator for collecting these scattered parts in order to prevent some problems in the management over the operation and the burden results in one of the causes for decreasing an efficiency of the operation. And this trend becomes more and more conspicuous as the number of general consumers for the film is increased with the spread of cameras and the improvements over this trend are demanded more and more by the consumers.
As a new technology which has been devised and developed for providing an improvement over these problems, U.S. Pat. No. 3,261,237 has been granted. In this patent the free end of the film which has already been rewound into the cartridge is pulled out of the cartridge by applying a careful handling of an elongated tool having a special shape. Another prior art approach is found in U.S. Pat. No. 3,864,993. In this patent an adhesive patch is applied at the leading end of a foldable blade in order to pull the free end of the film out of the cartridge. Yet further prior art is found in U.S. Pat. No. 4,047,653. This patent discloses curved inner and outer jaws which are movable with respect to one another, and the operation involves inserting the jaw ends into the cartridge, rotating the film within the cartridge until the free end is between the jaw ends, and grasping the film with the jaw ends. One drawback of these prior art devices is that they are manually operated which will require some skill of operation. Inefficiency is found at a processing laboratory where this kind of cartridge should be processed on a commercial basis and it is possible to say that these operations would cause some delay in a series of operations of developing etc.